JPH11336709A - Multistage cylinder apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent splashing of oil leaked from a ground portion of a multistage cylinder apparatus. SOLUTION: A multistage cylinder apparatus 1 comprises outermost basic cylinder tubes 11, a plurality of movable cylinder tubes 21 and 31 installed telescopically one by one inside of the basic cylinder tubes 11, and rod covers 22 and 32 provided at ends of the movable cylinder tubes 21 and 31. The multistage cylinder apparatus 1 is utilized by driving almost vertically the movable cylinder tubes 21 and 31. In the rod covers 22 and 32, guiding portions 23 and 33 are respectively disposed to make flow, along the outer peripheral surface of the movable cylinder tubes 21, 31, oil leaked from a gap between the rod cover 22 and movable cylinder tubes 31 and from a gap between the rod cover 32 and a piston rod 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-stage cylinder device improved so that oil leaking from a sliding contact portion between a rod and a rod cover does not splash around.

[0002]

2. Description of the Related Art Conventionally, a multi-stage cylinder device (telescopic cylinder device) is often used for a hydraulic elevator.

FIG. 7 shows a conventional multi-stage cylinder device 80 for a hydraulic elevator. As shown in FIG. 7, the multi-stage cylinder device 80 includes an outermost basic cylinder tube 81, and a movable cylinder tube 8 which is sequentially nested inside the basic cylinder tube 81.
2, 83 and a piston rod 84, a rod cover 91 attached to an end of a basic cylinder tube 81, a rod cover 92 attached to an end of a movable cylinder tube 82, a rod attached to an end of a movable cylinder tube 83 Cover 93 and rod covers 91 and 9
Rod packings 91P provided on the rods 2 and 93, respectively.
92P, 93P, etc.

A collecting groove 91 is formed on the upper end surface of the rod cover 91.
S and a drain tube 95 are provided. A transport basket is attached to the tip of the piston rod 84. In the multi-stage cylinder device 80, the basic cylinder tube 8
When pressurized oil is supplied to the fluid chamber 81A from a port (not shown) provided in 1, the movable cylinder tubes 82, 83 and the piston rod 84 move upward, and the basket moves upward. Conversely, when the pressure oil is discharged from the port, the movable cylinder tubes 82 and 83 and the piston rod 84 return downward, and the cage moves downward.

In the multi-stage type cylinder device 80, at the time of driving, the driving oil in the fluid chamber 81A is supplied to each of the gland portions, ie, the rod packings 91P, 92P, 93P and the movable cylinder tubes 82, 83 or the piston rod 84. It is configured to leak slightly from the gap between them. The leaked oil acts as a lubricating oil, smoothing the movement of the movable cylinder tubes 82 and 83 and the piston rod 84 by eliminating chatter and the like of the sliding portion. As a result, the vibration of the car and the like of the hydraulic elevator is reduced, and the riding comfort is improved.

By the way, the oil leaking from the gap between the rod packing 93P and the piston rod 84 flows down along the path shown by the arrow M1. Oil flowing from the rod cover 93 along the path indicated by the arrow M1, and the rod packing 92
Oil leaking from the gap between P and the movable cylinder tube 83 flows down the path indicated by the arrow M2.

That is, the oil flows in this order along the outer peripheral surface of the movable cylinder tube 83, the upper end surface, the outer peripheral surface, and the lower end surface of the rod cover 92, and the outer peripheral surface of the movable cylinder tube 83. Reach The collecting groove 91 provided on the upper end surface of the rod cover 91
It is collected in S and discharged to the outside of the multi-stage cylinder device 80 through the drain pipe 95.

[0008]

Now, in the conventional multi-stage cylinder device 80, the leaked oil is removed by the rod cover 9
When the oil reaches the lower end portions 93D and 92D of the outer peripheral surfaces of the third and the second 92, oil droplets are easily formed there. The lower ends of the rod covers 93 and 92 are tapered to allow oil to flow, but the inclination is gentle, so that the oil flows at a low speed.

Therefore, the oil that has been dropped at the lower end portions 93D and 92D, or the oil that is traveling along the respective peripheral surface portions, is accelerated or vibrated when the movable cylinder tubes 82 and 83 and the piston rod 84 operate. It may not be able to travel along the peripheral surface and may fall as drops. Then, the drop of the dropped oil becomes fine particles and scatters around, and contaminates the periphery of the multi-stage cylinder device 80. Also, the smell of oil will drift around it.

The multi-stage cylinder device 80 is often used as a hydraulic elevator for home use, and it is not preferable that the elevator car and the periphery of the floor are contaminated with oil and the oil smell drifts.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a multi-stage cylinder device in which oil leaking from a ground portion is prevented from scattering around.

[0012]

According to a first aspect of the present invention, there is provided an apparatus comprising: an outermost basic cylinder tube; a plurality of movable cylinder tubes nested inside the basic cylinder tube; A rod cover provided at an end of a movable cylinder tube, and in a multi-stage cylinder device used by driving the movable cylinder tube along a substantially vertical direction, each rod cover includes:
A guide portion is provided for guiding oil leaking from a gap between the rod cover and the movable cylinder tube to flow down along the outer peripheral surface of the movable cylinder tube provided with the rod cover.

In the apparatus according to a second aspect of the present invention, the guide portion is provided on an upper end surface of each of the rod covers, and has an annular collecting groove for collecting oil flowing on the upper end surface. And a communicating portion for guiding the oil collected in the collecting groove toward the outer peripheral surface of the movable cylinder tube.

According to a third aspect of the present invention, as the communication portion, a vertical hole drilled from the upper end surface side to the lower end surface side of the rod cover, and penetrates from the outer peripheral surface to the inner peripheral surface of the rod cover. And a horizontal hole communicating with the vertical hole is provided in the horizontal hole to prevent oil flowing through the communication portion from flowing outward in the radial direction of the rod cover, and the rod cover is provided with the rod cover. And a screw member for fixing to the movable cylinder tube.

According to a fourth aspect of the present invention, in the movable cylinder tube provided with the rod cover, a portion of the movable cylinder tube provided below the lower end of the rod cover is smaller than the inner diameter of the lower end of the rod cover. A large diameter portion having a large diameter is provided.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG. 1 is a front view showing a cross section of a part of a multi-stage cylinder device 1 according to a first embodiment of the present invention, and FIG. 2 is a multi-stage cylinder device. FIG. 3 is a cross-sectional view showing a main part of the rod cover 22 used in FIG. 1, and FIG.

In FIG. 1, a multi-stage cylinder device 1 comprises:
Basic cylinder tube 11, first-stage movable cylinder tube 21, second-stage movable cylinder tube 31, piston rod 41, rod covers 12, 22, 32, dust wipers 15, 25, 35, and rod packing 14,
24, 34 and the like.

The basic cylinder tube 11 is the outermost cylinder tube, and its lower end face is attached to a dedicated base and fixed to a pit of a building. Inside the basic cylinder tube 11, a first-stage movable cylinder tube 21, a second-stage movable cylinder tube 31, and a piston rod 41 are nested in this order.

A rod cover 12 is attached to the upper end of the basic cylinder tube 11, and a first-stage movable cylinder tube 21 slides on the inner peripheral surface of the rod cover 12.
A rod cover 22 is attached to the upper end of the first-stage movable cylinder tube 21, and the second-stage movable cylinder tube 31 slides on the inner peripheral surface of the rod cover 22.

A rod cover 32 is attached to the upper end of the second-stage movable cylinder tube 31, and a piston rod 41 slides on the inner peripheral surface of the rod cover 32. A transport basket is attached to the tip of the piston rod 41,
It is driven up and down by the multi-stage cylinder device 1.

The rod covers 12, 22, 32 are provided with guide portions 13, 23, 33, respectively. The guide portions 13, 23, and 33 serve as flow paths for leaked oil. The rod cover 22 includes a cylindrical sliding member 22W and a fixing member 22F.
It is composed of

The fixed member 22F has a female screw provided on the inner peripheral surface of the sliding member 22W sandwiched between the first-stage movable cylinder tube 21 and the fixed member 22F. It is attached to the first-stage movable cylinder tube 21 by being screwed into a male screw of the cylinder tube 21.

Referring to FIGS. 2 and 3, fixing member 22F
Has an outer peripheral surface that is a circular surface, and an annular recovery groove 23M that is concentric with the outer peripheral surface is provided on the upper end surface. Collection groove 2
The 3M prevents the oil flowing on the upper end surface of the fixing member 22F from going outside, and captures and recovers the oil. An annular hollow portion 23V concentric with the outer periphery is provided inside the lower portion of the fixing member 22F. Collection groove 2
The 3M and the hollow portion 23V are formed with a communication hole 23R formed in the vertical direction from the upper end surface side to the lower end surface side of the fixing member 22F.
Is in communication with Therefore, the oil collected in the collecting groove 23M flows down the communication hole 23R and flows down to the hollow portion 23V.

The guiding portion 23 is constituted by the collecting groove 23M, the hollow portion 23V, and the communication hole 23R. A narrow gap 23VE of about 0.5 to 1.0 mm is provided between the lower end 22FS of the fixed member 22F and the outer peripheral surface of the first-stage movable cylinder tube 21. Since the gap 23VE is narrow, the oil that has flowed into the hollow portion 23V is all transmitted to the outer peripheral surface of the first-stage movable cylinder tube 21 without forming droplets.

The first-stage movable cylinder tube 21
Is provided with a large-diameter portion 21D having a diameter larger than the inner diameter of the lower end portion 22FS at a portion below the lower end portion 22FS of the rod cover 22.

Returning to FIG. 1, the communicating portion 33 provided on the rod cover 32 has the same shape as the communicating portion 23 of the rod cover 22 described above. The second-stage movable cylinder tube 31 is also provided with a large-diameter portion 31D similar to the large-diameter portion 21D described above.

The upper end surface of the rod cover 12 is provided with an annular recovery groove 13M concentric with the outer periphery thereof. Further, the collection groove 13M opened in the lateral direction of the rod cover 12 is provided.
A communication hole 13 </ b> R is provided to communicate with the drain tube 16, and a drain tube 16 is attached to the communication hole 13 </ b> R.

Next, the flow path of the leaked oil in the multi-stage cylinder device 1 will be described. In FIG.
The oil leaking from each gland flows down the peripheral surface along a path indicated by an arrow.

As shown in FIG. 2, for example, oil leaked from the gap between the second-stage movable cylinder tube 31 and the rod cover 22 is collected by the collecting groove 23M, and
It flows out toward the outer peripheral surface of the movable cylinder tube 21 of the first stage through 3R. Lower end 22FS of fixing member 22F
23 between the outer peripheral surface of the movable cylinder tube 21 and
Since VE is as narrow as about 0.5 to 1.0 mm as described above, all the oil that has flowed into the hollow portion 23V is transmitted to the outer peripheral surface of the first-stage movable cylinder tube 21 without forming droplets. Flows.

The guiding portion 33 provided on the rod cover 32
Has the same action as the above-described guide portion 23, so that all of the oil flows along the outer peripheral surface of the second-stage movable cylinder tube 31 without forming droplets.

Therefore, oil does not stay on the lower end surfaces of the rod covers 22 and 32, and no oil drops are formed there. Therefore, even if acceleration or vibration occurs as in the case where the movable cylinder tubes 21 and 31 and the piston rod 41 operate, the oil does not drop as droplets, so that the surroundings are soiled by the oil or the oil around the periphery. The smell is prevented from drifting.

Further, for example, even if the gap 23VE is widened and oil droplets are formed at the lower end portion 22FS due to poor processing accuracy of the fixing member 22F or aging, etc. Since the fall is received by the large-diameter portion 21D, it flows along the outer peripheral surface of the first-stage movable cylinder tube 21 without falling below the large-diameter portion 21D. This also prevents oil from splashing around.

The large-diameter portion 31D provided on the movable cylinder tube 31 also has the same function as the large-diameter portion 21D, so that the oil is prevented from scattering around as well.

The oil that has flowed down the route shown by the arrow is
It flows down to the upper end surface of the rod cover 12 and the recovery groove 1
It is collected at 3M and discharged through a drain pipe 16 to an external tank or the like. The discharged oil is cleaned, for example, through a filter or the like, and then returned to the oil tank and reused. [Second Embodiment] FIG. 4 shows a rod cover 2 used in a multi-stage cylinder device 1A according to a second embodiment of the present invention.
FIG. 5 is a sectional view showing a main part of 2a, and FIG. 5 is an enlarged view showing a communication hole 23aR and a set screw 28 in the rod cover 22a.

The multi-stage cylinder device 1A has the same configuration as the multi-stage cylinder device 1 except for each rod cover. 4 and 5, the same components as those of the multi-stage cylinder device 1 are denoted by the same reference numerals.

In FIG. 4, the rod cover 22a includes a sliding member 22W and a fixing member 22aF. The fixing member 22aF has a collection groove 23aM and a communication hole 23 similar to the case of the fixing member 22F of the multi-stage cylinder device 1.
aR is provided. Collection groove 23aM and communication hole 23
The guidance part 23a is comprised by aR.

In the multi-stage cylinder device 1A, the communication hole 23aR includes a vertical hole 23aRT and a horizontal hole 23aRY. The vertical hole 23aRT extends from the upper end surface side of the fixing member 22aF to the lower end surface side so as not to penetrate the lower end surface of the fixing member 22aF. The horizontal hole 23aRY penetrates from the outer peripheral surface to the inner peripheral surface of the fixing member 22aF, and communicates with the vertical hole 23aRT.

As shown in FIG. 5, the side holes 23aR
A thread is provided on the inner peripheral surface of Y, and set screw 2
8 is attached. The set screw 28 is connected to the communication hole 2
It also has the function of preventing the oil flowing through 3aR from flowing outward in the radial direction of the fixing member 22aF.

The tip end of the set screw 28 is thin, and a flow path for oil flows is formed between the outer peripheral surface and the inner peripheral surface of the lateral hole 23aRY. Also, set screw 28
Are fastened in a state where the tip surface 28F is in contact with the threadless portion of the first-stage movable cylinder tube 21. Thereby, the fixing member 22aF is firmly fixed to the first-stage movable cylinder tube 21. Also,
Since the distal end surface 28F of the set screw 28 abuts on the portion of the outer peripheral surface of the movable cylinder tube 21 where the threaded portion is not formed, the fixing member 22aF
When attaching / detaching, the screw portion and the packing are prevented from being damaged. Further, in the fixing member 22aF, since the hollow portion 23V in the fixing member 22F is unnecessary, the processing or molding is easy.

As described above, the lateral hole 23aRY not only forms a part of the oil flow path but also serves as a mounting hole for the set screw 28. Therefore, there is no need to separately provide a horizontal hole dedicated to the set screw.

Although not shown, the rod cover attached to the end of the movable cylinder tube 31 of the second stage also has the same vertical and horizontal holes as those of the rod cover 22a described above. , A set screw similar to the set screw 28 is attached.

The path through which the leaked oil flows is as shown by the arrow in FIG. 4 and is the same as in the first embodiment. In this embodiment, the set screw 28 is provided in the lateral hole 23aRY, but a cap is provided in the lateral hole 23aRY to prevent oil from flowing out, and a screw hole for the set screw is separately provided. May be.

Third Embodiment FIG. 6 is a sectional view showing a main part of a rod cover 22b used in a multi-stage cylinder device 1B according to a third embodiment of the present invention.

The multi-stage cylinder device 1B has the same configuration as the multi-stage cylinder device 1 except for each rod cover. 6, the same components as those of the multi-stage cylinder device 1 are denoted by the same reference numerals.

The rod cover 22b includes a sliding member 22W and a fixed member 22bF. Fixing member 22bF
Has a tapered upper end surface. An annular concave portion 23b concentric with the outer peripheral surface is provided below the fixing member 22bF.
V is provided. A guide hole 23b is formed in the peripheral wall of the fixing member 22bF. The guide hole 23b is one through hole having a downward slope from the outer peripheral surface side to the inner peripheral surface side of the fixing member 22bF.

In the fixing member 22bF, the guide hole 23b
The diameter of the outer peripheral surface below is larger than the diameter of the outer peripheral surface above the guide hole 23b, where an oil receiver 22bU is formed.

The lower end portion 22bFS of the fixing member 22bF and 1
The gap 23bVE between the outer peripheral surface of the movable cylinder tube 21 at the stage is formed as narrow as about 0.5 to 1.0 mm as described above.

In FIG. 6, the arrows indicate the paths through which the oil flows. The leaked oil flows radially outward of the fixing member 22bF along the upper end surface of the fixing member 22bF, and
It flows down along the outer peripheral surface of F. Oil flowing down along the outer peripheral surface of the fixing member 22bF is guided to the guide hole 23b by the oil receiver 22bU. This prevents the oil from dripping below the fixing member 22bF. The oil that has entered the guide hole 23b is the first stage movable cylinder tube 2
1 flows toward the outer peripheral surface side and flows into the concave portion 23bV.

The oil that has flowed into the recess 23bV does not form any droplets, as in the case of the first embodiment.
It flows along the outer peripheral surface of the movable cylinder tube 21 of the stage. For this reason, oil does not scatter around.

In the first and second embodiments, one or more communication holes 23R and 23aR can be provided. In the third embodiment described above, the guide hole 23b is a single hole formed in a diagonal straight line direction, but may be a plurality of holes.

In the first to third embodiments, the number of stages of the multi-stage cylinder devices 1, 1A, 1B is three, but may be two or four or more. In addition, the configuration, structure, and shape of the whole or each part of the multi-stage cylinder device 1, 1A, 1B,
The material, dimensions, and the like can be appropriately changed according to the spirit of the present invention.

The multi-stage cylinder device of the present invention is applicable not only to elevators but also to multi-stage jacks or cylinder devices for raising and lowering lighting devices, raising and lowering signboards, and various other uses.

[0053]

According to the first to fourth aspects of the present invention,
Since the leaked oil does not form droplets, the oil is prevented from splashing around.

According to the third aspect of the present invention, there is no need to separately provide a horizontal hole dedicated to the set screw. According to the invention of claim 4, even if an oil droplet is formed in the case where the accuracy of the rod cover is low or the like, the drop of the oil droplet is received by the large diameter portion, and the oil scatters around. Is prevented.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a multi-stage cylinder device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of a rod cover.

FIG. 3 is a plan view of a rod cover.

FIG. 4 is a cross-sectional view illustrating a main part of a rod cover used in a multi-stage cylinder device according to a second embodiment.

FIG. 5 is an enlarged view showing a communication hole and a set screw.

FIG. 6 is a cross-sectional view illustrating a main part of a rod cover used in a multi-stage cylinder device according to a third embodiment.

FIG. 7 is a partial cross-sectional view of a conventional multi-stage cylinder device for a hydraulic elevator.

[Explanation of symbols]

 1, 1A, 1B Multi-stage type cylinder device 11 Basic cylinder tube 12, 22, 32 Rod cover 13, 23, 33 Guiding part 21, 31 Movable cylinder tube 21D, 31D Large diameter part 22FS, 22bFS Lower end part 23M, 23aM Collection groove 23R , 23aR communication hole (communication part) 23V hollow part (communication part) 23b guide hole (guide part) 23aRT vertical hole 23aRY side hole 28 screw member

Claims (4)

[Claims] An outermost basic cylinder tube, a plurality of movable cylinder tubes nested sequentially inside the basic cylinder tube, and a rod cover provided at an end of each movable cylinder tube. In the multi-stage cylinder device which is used by driving the movable cylinder tube along a substantially vertical direction, the rod cover is provided with oil leaking from a gap between the rod cover and the movable cylinder tube and coming out of the rod. A multi-stage type cylinder device, comprising: a guide portion for guiding the movable cylinder tube to flow down along the outer peripheral surface of the movable cylinder tube provided with the cover. 2. The guide portion is provided on an upper end surface of each of the rod covers, and has an annular recovery groove for recovering oil flowing on the upper end surface. The guide portion communicates with the recovery groove and is recovered by the recovery groove. 2. The multi-stage cylinder device according to claim 1, further comprising a communication portion that guides the oil that has flowed toward an outer peripheral surface of the movable cylinder tube. 3. A vertical hole drilled from an upper end surface side to a lower end surface side of the rod cover as the communication portion, and a horizontal hole penetrating from the outer peripheral surface to the inner peripheral surface of the rod cover and communicating with the vertical hole. Is provided in the side hole to prevent oil flowing through the communicating portion from flowing outward in the radial direction of the rod cover and to fix the rod cover to a movable cylinder tube provided with the rod cover. The multi-stage cylinder device according to claim 2, wherein the screw member is provided. 4. The movable cylinder tube provided with the rod cover has a large-diameter portion having a diameter larger than the inner diameter of the lower end of the rod cover in a portion below the lower end of the rod cover. The multi-stage cylinder device according to claim 1, wherein the cylinder device is provided.